scholarly journals Detecting Endogenous Growth Regulators on the Sarcotesta, Sclerotesta, Endosperm, and Embryo by Paper Chromatography on Fresh and Old Seeds of Two Papaya Varieties

1969 ◽  
Vol 64 (2) ◽  
pp. 164-172
Author(s):  
Manuel N. Reyes ◽  
Agripino Pérez ◽  
José Cuevas
Keyword(s):  
Endogenous Growth ◽  
Paper Chromatography ◽  
Growth Regulators ◽  
Growth Inhibitor ◽  
Natural Growth ◽  
Growth Inhibitors ◽  
Growth Promoters ◽  
Gelatinous Envelope ◽  
Papaya Seeds

Sarcotesta, sclerotesta, endosperm and embryo of fresh and old (0 and 3 years, respectively) seeds of the P.R. 6-65 and P.R. 8-65 papaya varieties were separately analyzed by paper chromatography to determine the presence of natural growth inhibitor that might be responsible for the reduction in germination of papaya seeds during storage. The results showed that in the innermost seed parts (embryo and endosperm) endogenous growth promoters were found while the outermost structures (sarcotesta and sclerotesta) contained inhibitors. Therefore, it is possible that the natural growth inhibitors of this seed might be minimized by removing the sarcotesta (the gelatinous envelope) of the seed, which contains the most endogenous growth inhibitors, plus a careful washing to eliminate the soluble inhibitors of the sclerotesta during the extraction of seeds from the fruits.

Effect of Growth Regulators on Stomatal Structure and Development in the Cotyledons of Lagenaria leucantha (Duch.) Rusby

1975 ◽  
Vol 23 (1) ◽  
pp. 13 ◽  
Author(s):  
JA Inamdar ◽  
M Gangadhara
Keyword(s):  
Growth Regulators ◽  
Growth Inhibitor ◽  
Guard Cells ◽  
Inhibitory Effect ◽  
Subsidiary Cell ◽  
Growth Promoter ◽  
Stomatal Index ◽  
Stomatal Frequency ◽  
Growth Promoters ◽  
High Concentration

In untreated cotyledons (controls) anomocytic stomata and stomata with a single subsidiary cell were observed. In cotyledons treated with growth regulators, anisocytic, paracytic, cyclocytic and several abnormal stomatal types were observed in addition to those found in the controls. Gibberellic acid, though a growth promoter, acted as an inhibitor at high concentration. Ascorbic acid at 25 p.p.m. increased the stomatal index and the size of guard cells, while the stomatal frequency decreased. Sucrose at 2000 p.p.m. increased the stomatal index and the length of guard cells. 2,3,5-Tri-iodobenzoic acid caused degeneration of guard cells and acted as a growth inhibitor at higher concentrations. As the concentration of kinetin increased, decreases in the stomatal frequency, index and size of guard cells were noted. Kinetin also induced the formation of contiguous stomata and the division of guard cells. Sulphanilamide could act either as an inhibitor or as a promoter as its concentration increased. Coumarin at 50 p.p.m. reduced the size of guard cells and the stomatal frequency, and commonly induced persistent stomatal initials, while at 100 p.p.m. only the radicle emerged and the cotyledons failed to emerge from the seed-coat. Increased concentrations of colchicine promoted more induction of persistent stomatal initials, and inhibited stomatal formation as was evidenced by a reduced stomatal frequency and index. Colchicine at 50 p.p.m. induced formation of double pores in a stoma, abnormally large pore sizes, and increases in the size of guard cells and their nuclei. With maleic hydrazide the sizes of guard and epidermal cells were reduced and persistent stomatal initials occasionally formed. Growth promoters could sometimes interact with inhibitors to overcome their inhibitory effect, depending on the substances used in combination and their concentrations.

scholarly journals Programming cell growth into different cluster shapes using diffusible signals

2020 ◽  
Author(s):  
Yipei Guo ◽  
Mor Nitzan ◽  
Michael P. Brenner
Keyword(s):  
Growth Regulators ◽  
Growth Inhibitor ◽  
Spatial Arrangement ◽  
Cell Types ◽  
Growth Inhibitors ◽  
Genetic Circuits ◽  
Regulatory Circuits ◽  
Differential Gene ◽  
Different Shapes ◽  
Different Cell Types

Recent advances in genetic engineering technologies has made it possible to construct artificial genetic circuits and use them to control how cells respond to their surroundings. This has been used to generate spatial patterns of differential gene expression. In addition to the spatial arrangement of different cell types, another important aspect of spatial structure lies in the overall shape of the group of cells. However, the question of how cells can be programmed, and how complex the rules need to be, to achieve a desired tissue morphology has received less attention. In this paper, we attempt to address these questions by developing a mathematical model to study how cells can use diffusion-mediated local rules to grow into clusters with different shapes. Within our model, cells are allowed to secrete diffusible chemicals which can either directly regulate the growth rate of cells (‘growth regulator’), or indirectly affect growth by changing the secretion rate or the effect of other growth regulators. We find that (1) a single growth inhibitor can be used to grow a rod-like structure, (2) multiple growth regulators are required to grow multiple protrusions, and (3) the length and shape of each protrusion can be controlled using growth-threshold regulators. Based on these regulatory schemes, we also postulate how the range of achievable structures scales with the number of signals: (A) the maximum possible number of protrusions increases exponentially with the number of growth inhibitors involved, and (B) to control the growth of each set of protrusions, it is necessary to have an independent threshold regulator. Together, these experimentally-testable findings illustrate how our approach can be used to guide the design of regulatory circuits for achieving a desired target structure.

scholarly journals In VitroInhibition ofHelicobacter pyloriGrowth by Redox Cycling Phenylaminojuglones

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Julio Benites ◽  
Héctor Toledo ◽  
Felipe Salas ◽  
Angélica Guerrero ◽  
David Rios ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Antibacterial Activity ◽  
Active Compound ◽  
Metabolic Pathways ◽  
Growth Inhibitor ◽  
Growth Inhibitors ◽  
Design Synthesis ◽  
H Pylori

Infection byHelicobacter pyloriincreases 10 times the risk of developing gastric cancer. Juglone, a natural occurring 1,4-naphthoquinone, preventsH. pylorigrowth by interfering with some of its critical metabolic pathways. Here, we report the design, synthesis, andin vitroevaluation of a series of juglone derivatives, namely, 2/3-phenylaminojuglones, as potentialH. pylorigrowth inhibitors. Results show that 5 out of 12 phenylaminojuglones (at 1.5 μg/mL) were 1.5–2.2-fold more active than juglone. Interestingly, most of the phenylaminojuglones (10 out of 12) were 1.1–2.8 fold more active than metronidazole, a knownH. pylorigrowth inhibitor. The most active compound, namely, 2-((3,4,5-trimethoxyphenyl)amino)-5-hydroxynaphthalene-1,4-dione 7, showed significant higher halo of growth inhibitions (HGI = 32.25 mm) to that of juglone and metronidazole (HGI = 14.50 and 11.67 mm). Structural activity relationships of the series suggest that the nature and location of the nitrogen substituents in the juglone scaffold, likely due in part to their redox potential, may influence the antibacterial activity of the series.

EFFECTS OF DIFFERENT AFTER-RIPENING TREATMENTS ON GERMINATION AND ENDOGENOUS GROWTH INHIBITORS IN ROSA RUGOSA

1972 ◽  
Vol 52 (6) ◽  
pp. 1049-1058 ◽  
Author(s):  
F. J. SVEJDA ◽  
P. A. POAPST
Keyword(s):  
Abscisic Acid ◽  
Effective Treatment ◽  
Endogenous Growth ◽  
Lepidium Sativum ◽  
Growth Inhibitors ◽  
Germination Inhibitors ◽  
Rosa Rugosa ◽  
Ripening Period ◽  
Retarding Effect ◽  
Lepidium Sativum L

The concentration of growth and germination inhibitors in achenes from seedlings of R. rugosa Thunberg is reduced through leaching. Leaching of achenes for 24 hr before stratification increased the germination but the effect of leaching was not always significant. The presence of inhibitors was indicated between Rf 0.3–0.4 and Rf 0.7–0.9 by the retarding effect on radicle elongation of cress seeds (Lepidium sativum L. cult Moss Curled) when extracts of achenes were developed on ascending paper chromatograms (isopropanol:ammonia:water, 10:1:1, v/v). Changed concentrations of the inhibitor between Rf 0.7 and 0.9 from different after-ripening treatments did affect the germination of the achenes but the changed concentrations of the inhibitor between Rf 0.3 and 0.4 did not. Presumably, the inhibitor between Rf 0.7 and 0.9 was abscisic acid. Warm–cold treatments promoted germination more effectively than cold treatments. The most effective treatment was 4 weeks at 20 C and 8 weeks at 4 C. Both cold and warm–cold after-ripening seemed to promote germination through a reduction of growth inhibitors. Inhibitors do not control the germination of rose achenes exclusively because: (a) leaching reduced the concentration of inhibitors but it did not induce germination without after-ripening treatments; (b) partial after-ripening for 4 weeks at 20 C also reduced the concentration of inhibitors but it did not induce germination unless it was followed by an after-ripening period of 4 C; (c) after-ripened achenes germinated in spite of inhibitors.

Plant Hormones and Other Endogenous Growth Regulators

1997 ◽  
pp. 309-319
Author(s):  
Theodore T. Kozlowski ◽  
Stephen G. Pallardy
Keyword(s):  
Endogenous Growth ◽  
Growth Regulators ◽  
Plant Hormones

Natural Growth Regulators

1976 ◽  
pp. 526-616 ◽  
Author(s):  
H. M. Dekhuijzen ◽  
G. F. Pegg
Keyword(s):  
Growth Regulators ◽  
Natural Growth

A Comparative Risk Assessment for Listeria monocytogenes in Prepackaged versus Retail-Sliced Deli Meat

2010 ◽  
Vol 73 (4) ◽  
pp. 612-619 ◽  
Author(s):  
SARAH ENDRIKAT ◽  
DANIEL GALLAGHER ◽  
RÉGIS POUILLOT ◽  
HEATHER HICKS QUESENBERRY ◽  
DAVID LaBARRE ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Sensitivity Analysis ◽  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Risk Ratio ◽  
Growth Inhibitor ◽  
Assessment Model ◽  
Growth Inhibitors ◽  
Comparative Risk ◽  
Inspection Service

Deli meat was ranked as the highest-risk ready-to-eat food vehicle of Listeria monocytogenes within the 2003 U.S. Food and Drug Administration and U.S. Department of Agriculture, Food Safety and Inspection Service risk assessment. The comparative risk of L. monocytogenes in retail-sliced versus prepackaged deli meats was evaluated with a modified version of this model. Other research has found that retail-sliced deli meats have both higher prevalence and levels of L. monocytogenes than have product sliced and packaged at the manufacturer level. The updated risk assessment model considered slicing location as well as the use of growth inhibitors. The per annum comparative risk ratio for the number of deaths from retail-sliced versus prepackaged deli meats was found to be 4.89, and the per-serving comparative risk ratio was 4.27. There was a significant interaction between the use of growth inhibitors and slicing location. Almost 70% of the estimated deaths occurred from retail-sliced product that did not possess a growth inhibitor. A sensitivity analysis, assessing the effect of the model's consumer storage time and shelf life assumptions, found that even if retail-sliced deli meats were stored for a quarter of the time prepackaged deli meats were stored, retail-sliced product is 1.7 times more likely to result in death from listeriosis. Sensitivity analysis also showed that the shelf life assumption had little effect on the comparative risk ratio.

Sign in / Sign up

Export Citation Format

Share Document